CN112805586B - Laser emission circuit and laser radar - Google Patents
Laser emission circuit and laser radar Download PDFInfo
- Publication number
- CN112805586B CN112805586B CN201980064663.0A CN201980064663A CN112805586B CN 112805586 B CN112805586 B CN 112805586B CN 201980064663 A CN201980064663 A CN 201980064663A CN 112805586 B CN112805586 B CN 112805586B
- Authority
- CN
- China
- Prior art keywords
- energy
- circuit
- storage capacitor
- transistor
- charging
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- G01S7/00—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00
- G01S7/48—Details of systems according to groups G01S13/00, G01S15/00, G01S17/00 of systems according to group G01S17/00
- G01S7/483—Details of pulse systems
- G01S7/484—Transmitters
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
- H01S5/00—Semiconductor lasers
- H01S5/04—Processes or apparatus for excitation, e.g. pumping, e.g. by electron beams
- H01S5/042—Electrical excitation ; Circuits therefor
Abstract
A laser emission circuit and a laser radar belong to the field of laser radars. The Laser Diode (LD) is changed from original connection with the drain electrode of the energy release switching element (Q2) to connection with the second end of the energy storage capacitor (C2), the second end of the energy storage capacitor (C2) is grounded through the cathode of the Laser Diode (LD), the second end of the energy storage capacitor (C2) is suspended through the Laser Diode (LD), namely the second end of the energy storage capacitor (C2) is not directly grounded, and the parasitic capacitance of the energy release switching element (Q2) does not cause the Laser Diode (LD) to emit light in advance due to the energy conversion charging process in the energy conversion stage, so that the Laser Diode (LD) is prevented from emitting light in unexpected time, and the problem of laser light leakage is solved.
Description
Technical Field
The application relates to the field of laser circuits, in particular to a laser transmitting circuit and a laser radar.
Background
In the laser radar, a laser transmitting circuit is used for transmitting laser, and the working process of the laser transmitting circuit is generally divided into three stages: the energy charging stage comprises charging an energy storage element, storing electric energy in the energy storage element, the energy conversion stage comprises transferring the electric energy stored on the energy storage element to an energy conversion element after the energy charging stage is completed, and the energy releasing stage comprises releasing the electric energy stored on the energy conversion element to drive a laser diode to emit laser after the transfer of the electric energy is completed. Along with the development of the laser radar, the laser radar is required to complete the energy charging stage in a shorter time at present, but the inventor finds that in the process of reducing the energy charging time, the original laser emission circuit can emit laser in advance in the energy conversion stage, so that the phenomenon of laser light leakage is caused, namely the laser emission circuit emits light in unexpected time, and the measurement performance of the laser radar can be affected.
Disclosure of Invention
The laser emission circuit and the laser radar provided by the embodiment of the application can solve the problem of laser light leakage caused by the emission of laser in the energy conversion stage of the laser emission circuit in the related technology. The technical scheme is as follows:
in a first aspect, an embodiment of the present application provides a laser emission circuit, including:
the energy charging circuit is connected with the energy conversion circuit and is used for storing electric energy;
the energy conversion circuit is connected with the energy charging circuit and the energy releasing circuit and is used for converting the electric energy stored in the energy charging circuit into the energy conversion circuit; the energy conversion circuit comprises an energy storage capacitor and a floating diode, wherein the first end of the energy storage capacitor is connected with the energy charging circuit, and the first end of the energy storage capacitor is connected with the first end of the energy release switch element; the second end of the energy storage capacitor is connected with the anode of the floating diode, the second end of the energy storage capacitor is connected with the energy release circuit, and the cathode of the floating diode is grounded;
the energy release circuit is connected with the energy conversion circuit and is used for driving the laser diode to emit light by utilizing the electric energy stored in the energy conversion circuit; the energy release circuit comprises an energy release switch element and the laser diode, wherein the first end of the energy release switch element is connected with the first end of the energy storage capacitor, the second end of the energy release switch element is grounded, the second end of the energy release switch element is connected with the anode of the laser diode, and the cathode of the laser diode is connected with the second end of the capacitor.
In a second aspect, an embodiment of the present application provides a laser radar, including the laser transmitting circuit described above.
The technical scheme provided by the embodiments of the application has the beneficial effects that at least:
the laser diode is changed from original connection with the drain electrode of the energy release switch element to connection with the second end of the energy storage capacitor, the second end of the energy storage capacitor is grounded through the cathode of the laser diode, and the second end of the energy storage capacitor is suspended through the laser diode, namely, the second end of the energy storage capacitor is not directly grounded any more.
Drawings
In order to more clearly illustrate the embodiments of the application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described, it being obvious that the drawings in the following description are only some embodiments of the application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a related art laser emission circuit according to an embodiment of the present application;
FIG. 2 is a block diagram of a laser emitting circuit provided by an embodiment of the present application;
fig. 3 is a schematic diagram of a laser transmitting circuit according to an embodiment of the present application;
fig. 4 is another schematic structural diagram of a laser transmitting circuit according to an embodiment of the present application.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the following detailed description of the embodiments of the present application will be given with reference to the accompanying drawings.
Fig. 1 shows a schematic diagram of a laser emission circuit in the related art, and the operation of the laser emission circuit is divided into three stages: the charging stage, the energy conversion stage and the energy release stage are respectively described in detail below.
And (3) energy charging stage: the grid electrode of the switching tube Q1 is connected with a pulse generator TX_CHG, and the pulse generator TX_CHG sends rectangular pulses to control the on and off of the switching tube Q1; the pulse generator tx_en transmits a rectangular pulse to control the on and off of the switching transistor Q2. When the switching tube Q1 is in an on state and the switching tube Q2 is in an off state, the laser emission circuit is in a charging stage. The current generated by the power supply VCC passes through the inductor L1 and the switching tube Q1 to form a loop, and charges the inductor L1. Assuming that the on-time of the switching tube Q1 is Δt (Δt is also called charging time), the current increment in the inductor L1 obeys the formula: Δi= (vcc×Δt)/L1 (formula 1).
Wherein VCC in formula 1 represents a voltage value of the power supply VCC, and L1 represents an inductance value of the inductor L1.
The energy of charging obeys the formula
Substituting equation 1 into equation 2 yieldsAs can be seen from equation 3, the charging energy W L Inversely proportional to the inductance L1 and proportional to the square of the on-time Δt of the switching tube Q1. At the time of maintaining the charging energy W L If the on time of the switching transistor Q1 is to be reduced, the inductance value of the inductor L1 needs to be reduced.
As can be seen from the formulas 1 and 2, the pulse generator tx_chg can control the width of the rectangular pulse to control the on time of the switching tube Q1, i.e. the charging time of the inductor L1, so as to change the charging energy and adjust the emission power of the laser.
Energy conversion stage: when the switching tube Q1 is in an off state and the switching tube Q2 is also in an off state, the laser emission circuit is in a transduction stage. Because the current of the inductor L1 cannot be suddenly changed, the inductor L1 stores charging electric energy, and the inductor L1 charges the energy storage capacitor C2 through the boost rectifier diode D1, so that the charging electric energy stored in the inductor L1 is transferred to the energy storage capacitor C2.
Although the switching transistor Q1 and the switching transistor Q2 are in an off state, a parasitic capacitance exists between the drain and the source of the two switching transistors, and the parasitic capacitance between the drain and the source of the switching transistor Q1 is defined as C Q1-DS The parasitic capacitance between the drain and source of the switching tube Q2 is C Q2-DS 。
The current increment Δi of the inductance L1 will be split by three branches:
loop 1: the current flows from the inductance L1 through the parasitic capacitance C Q1-DS To ground GND to form a loop, defining the current on the loop as I CQ1 。
Loop 2: the current forms a loop from the inductor L1 to the ground GND through the boost rectifying diode D1 and the energy storage capacitor C2, and the current on the loop is defined as I C2 。
Loop 3: the current is led from L1 to the voltage boosting rectifier diode D1, the laser diodes LD and C Q2-DS Form a loop to Ground (GND), define a current as I CQ2 。
Only the loop 2 of the above 3 loops is a main charging loop, so that the energy storage effect on the energy storage capacitor C2 is realized, and the loops 1 and 3 are both caused by parasitic capacitance.
Considering that the forward voltage drops of the boost rectifier diode D1 and the laser diode LD are relatively small, the influence on each loop is small, and the voltage drop influence of the boost rectifier diode D1 and the laser diode LD on the loop is ignored for the sake of simplifying calculation, Δi=i can be obtained C2 +I CQ1 +I CQ2 (equation 4).
Suppose C Q1-DS ＝C Q2-DS ＝C 2 N, N is a number greater than 0, C Q1-DS Capacitance value C representing parasitic capacitance of switching tube Q1 Q2-DS Capacitance value C representing parasitic capacitance of switching tube Q2 2 The capacitance value of the storage capacitor C2 is represented. The value of the current flowing through each loop is:
as can be seen from loop 3, I CQ2 Equal to laser lightCurrent I of diode LD LD I.e. I CQ2 ＝I LD (equation 8). Let the current threshold of LD luminescence be I LD-TH If I CQ2 Greater than the current threshold greater than I LD-TH The laser diode LD emits laser in the energy conversion stage, which causes a light leakage phenomenon, i.e., the laser emission circuit emits light in unexpected time, which affects the measurement performance of the laser radar.
For example: in order to meet the overall performance of lidar, for example: the system frequency point is increased, the functions of double emission, multiple emission and the like are realized, and the charging time delta t is required to be reduced.
At the energy W of the holding inductance L1 L On the premise that the voltage value of the power supply VCC is unchanged, it can be seen from equation 3 that the inductance value of the inductance L1 in the charging circuit needs to be correspondingly reduced. Then, as can be seen from equation 1, if the inductance value of the inductor L1 decreases, the charging current Δi generated by the inductor L1 increases accordingly. Finally, as can be seen from equations 7 and 8, when the charging current ΔI increases, the current flowing through the laser diode LD during the energy conversion process also increases, so that the current flowing through the laser diode LD may satisfy I CQ2 ＝I LD ≥I LD-TH The laser diode LD emits light at an unexpected time, resulting in a "laser light leakage" phenomenon.
Energy release stage: when the switching tube Q1 is in an off state and the switching tube Q2 is in an on state, the laser emission circuit is in an energy release stage. The energy stored in the energy storage capacitor C2 forms a loop through the laser diode LD and the switching tube Q2 to the ground GND, so as to drive the laser diode LD to emit laser light, thereby enabling the laser diode LD to emit laser light at the expected time.
In order to solve the above technical problems, an embodiment of the present application provides a laser emission circuit, as shown in fig. 2, including: a charging circuit 201, an energy conversion circuit 202 and an energy release circuit 203. The charging circuit 201 is connected with the energy conversion circuit 202, and the energy conversion circuit 202 is connected with the energy release circuit 203. The charging circuit 201 is used for storing electric energy, the energy conversion circuit 202 is used for converting the electric energy stored in the charging circuit 201 into energy conversion circuit, and the energy release circuit 203 is used for driving the laser diode to emit light by the electric energy stored in the energy conversion circuit 202.
Referring to fig. 3, a schematic diagram of a transduction circuit 202 and a de-energized circuit 203 according to an embodiment of the application is shown, wherein the transduction circuit 202 includes a storage capacitor C2 and a floating diode D2. The energy release circuit 203 includes an energy storage capacitor C2, an energy release switching element and a laser diode LD, where the energy release switching element includes two switch ends and a control end (not shown in fig. 2), and a control signal (e.g., a pulse signal) is input into the control end to control the two switch ends to be turned on or off, so as to implement an on state or an off state of the energy release switching element. The energy release switching element may be GaN (gallium nitride switching tube), MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), or IGBT (Insulated Gate Bipolar Transistor ).
The connection relation of each element in the energy conversion circuit 202 and the energy release circuit 203 is as follows: a first end of the energy storage capacitor C2 is connected with the energy charging circuit 201, and a first end of the energy storage capacitor C2 is connected with a first end of the energy release switching element; the second end of the energy storage capacitor C2 is connected with the anode of the floating diode D2, and the second end of the energy storage capacitor C2 is connected with the cathode (K) of the laser diode LD; the cathode of the floating diode D2 is grounded, the anode (a) of the laser diode LD is grounded, and the anode of the laser diode LD is connected to the second terminal of the energy release switching element. The first end and the second end of the energy release switching element in the embodiment refer to two switching ends of the energy release switching element.
The operation of the laser emission circuit in fig. 3 includes:
in the charging phase, the energy storage element in the charging circuit 201 stores the electric energy supplied by the power supply, and after the charging operation is completed, the energy conversion phase is performed.
In the energy conversion stage, the energy release switch element is in an off state, namely, two ends of the energy release switch element are open-circuited. The charging circuit 201 charges the energy conversion circuit 202 with the stored electric energy, specifically, transfers the electric energy to the energy storage capacitor C2 in the energy conversion circuit 202. Although the energy release switch element is in an off state, a certain parasitic capacitance exists in the energy release switch element, in fact, the current from the charging circuit 201 forms two loops, one loop is formed by the energy storage capacitor C2 and the floating diode D2 to the ground GND, and during the charging process of the energy storage capacitor C2, the laser emitting tube LD is in a reverse bias off state, and the energy conversion operation is completed. The other loop is formed by parasitic capacitance of the energy release switch element to the ground GND, so that the two loops can not pass through the laser diode LD any more, and the laser diode can not generate laser light leakage in the energy conversion stage, namely, can not emit light in unexpected time, thereby solving the problem of laser light leakage. After the energy conversion of the energy storage capacitor C2 is completed, an energy release stage is carried out.
In the energy release stage, the energy release switch is in a conducting state, and the electric energy stored on the energy storage capacitor returns to the second end of the energy storage capacitor through the two ends of the energy release switch element and the laser diode LD to form an energy release loop to drive the laser diode LD to emit light.
In one embodiment, the energy conversion circuit further includes a boost rectifying diode, an anode of the boost rectifying diode is connected to the energy charging circuit 201, a cathode of the boost rectifying diode is connected to the first end of the energy storage capacitor C2, the boost rectifying diode has a unidirectional conduction function, only the energy charging circuit 201 is allowed to charge the energy storage capacitor C2 in the energy conversion stage, and backflow of electric energy in the energy storage capacitor C2 caused by the energy storage capacitor C2 when the electric potential of the energy storage capacitor C2 is higher than that of the energy charging circuit 201 is avoided. Wherein it is understood that the boost rectifier diode may be a schottky diode.
In one or more embodiments, the energy release switching element is a transistor, a collector of the transistor is connected to the first end of the energy storage capacitor C2, an emitter of the transistor is grounded, an emitter of the transistor is connected to an anode of the laser diode LD, and a base of the transistor is connected to an output of the first pulse generator. The first pulse generator may emit a pulse, for example a rectangular pulse, which is high to control the conduction between the collector and emitter of the transistor; the low level of the rectangular pulse controls the disconnection between the collector and the emitter of the transistor, and the high level duration of the rectangular pulse is the on time of the transistor.
In one or more embodiments, the energy release switching element is a transistor, an emitter of the transistor is connected to the first end of the energy storage capacitor C2, a collector of the transistor is grounded, a collector of the transistor is connected to an anode of the laser diode LD, and a base of the transistor is connected to an output of the first pulse generator. The first pulse generator may emit a pulse, for example a rectangular pulse, which controls the break between the collector and the emitter of the transistor at a high level; the conduction between the collector and the emitter of the transistor is controlled by the rectangular pulse with the low level, and the duration of the low level of the rectangular pulse is the conduction time of the transistor.
In one or more embodiments, the energy release switching element is a gallium nitride (GaN) switching tube, the gallium nitride switching tube is a MOS (Metal Oxide Semiconductor ) tube, a drain electrode of the gallium nitride switching tube is connected to the first end of the energy storage capacitor C2, a source electrode of the gallium nitride switching tube is grounded, a source electrode of the gallium nitride switching tube is connected to an anode of the laser diode, and a gate electrode of the gallium nitride switching tube is connected to an output end of the first pulse generator. The first pulse generator can send out pulses, such as rectangular pulses, to control the connection or disconnection between the collector and the emitter of the gallium nitride switching tube, and the duration of the rectangular pulses is the connection time of the gallium nitride switching tube.
In one or more embodiments, the charging circuit includes a power supply, a decoupling capacitance, an inductance, and a charging switching element. The power supply is a direct current power supply, the positive electrode of the power supply is connected with the first end of the inductor, the second end of the inductor is grounded through the charging switch element, and the second end of the inductor is connected with the first end of the energy storage capacitor C2. The decoupling capacitance is used to cancel parasitic coupling between circuits. When the charging switch element is in a conducting state, the power supply charges the inductor, and after the charging is completed, electric energy is stored in the inductor. Wherein the charge switching element can be a GaN switch tube, a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor, metal Oxide semiconductor field effect transistor) or an IGBT (Insulated Gate Bipolar Transistor )
Further, the charging switch element is a transistor, the collector of the transistor is connected with the first end of the energy storage capacitor C2, the emitter of the transistor is grounded, and the base of the transistor is connected with the output end of the second pulse generator; the second pulse generator is in a conducting state by outputting a high level control transistor and is in a disconnecting state by outputting a low level control transistor; or (b)
The energy charging switch element is a transistor, an emitter of the transistor is connected with a first end of the energy storage capacitor C2, a collector of the transistor is grounded, a base of the transistor is connected with an output end of the second pulse generator, the second pulse generator is in an off state by outputting a high-level control transistor, and the second pulse generator is in an on state by outputting a low-level control transistor; or (b)
The charging switch element is a gallium nitride switch tube, the drain electrode of the gallium nitride switch tube is connected with the first end of the energy storage capacitor C2, the source electrode of the gallium nitride switch tube is grounded, and the grid electrode of the gallium nitride switch tube is connected with the output end of the second pulse generator. The second pulse generator is used for controlling the on time of the charging switch element.
In one or more embodiments, the energy release circuit 203 further includes a dynamic compensation capacitor connected across the energy release switch element, and the dynamic compensation capacitor is connected across the two switch ends of the energy release switch element. The dynamic compensation capacitor can restrain current resonance caused by parasitic parameters of a discharge loop of the energy storage capacitor C2 and supplement dynamic impedance when the energy release switching element is conducted.
In one or more embodiments, the capacitance value of the dynamic compensation capacitance is less than the capacitance value of the storage capacitance.
In one or more embodiments, the energy storage capacitor C2 may be formed by connecting a plurality of capacitors in parallel, so as to reduce ESR (Equivalent Series Resistance ) of the energy storage capacitor C2. It is understood that the capacitance values of the plurality of capacitors may be equal or different. Preferably, the capacitance values of the plurality of parallel capacitors are equal, the ESR consistency of the parallel capacitors with equal capacitance values is better, the discharge of the parallel capacitors is more equal, and the efficiency of the energy storage capacitor can be better improved.
It will be appreciated that the connection mode of the ground of each component in fig. 3 (e.g., the floating diode D2, the laser diode LD and the energy release switch element) may be changed to be connected to the negative electrode of the power supply, and the same function as the laser emitting circuit in fig. 3 may be realized. Wherein it is understood that the negative electrode of the power supply may be grounded.
Referring to fig. 4, a specific structural schematic diagram of a laser emitting circuit according to an embodiment of the present application is provided, in an embodiment of the present application, a charging circuit 201 includes a power source VCC, an inductor L1, a decoupling capacitor C1, and a MOS transistor Q1, where the MOS transistor Q1 is a charging switching element. The energy conversion circuit 202 includes a boost rectifier diode D1, an energy storage capacitor C2, and a floating diode D2. The energy release circuit 203 comprises an energy storage capacitor C2, a MOS tube Q2, a dynamic compensation capacitor C3 and a laser diode LD, wherein the MOS tube Q2 is used as an energy release switching element.
The connection relationship of the respective elements in fig. 4 is: the negative electrode of the power supply VCC is grounded, the positive electrode of the power supply VCC is grounded through a decoupling capacitor C1, the positive electrode of the power supply VCC is also connected with an inductor L1 and the drain electrode (D) of the MOS tube Q1, and the drain electrode of the MOS tube Q1 is simultaneously connected with the anode of the boost rectifying diode D1; the source electrode (S) of the MOS tube Q1 is grounded, and the grid electrode (G) of the MOS tube Q1 is connected with the output end of the pulse generator TX_CHG.
The cathode of the boost rectifying diode D1 is connected with the first end of the energy storage capacitor C2, and the cathode of the boost rectifying diode D2 is also connected with the drain electrode (D) of the MOS tube Q2. The second end of the energy storage capacitor C2 is connected with the anode of the floating diode D2, and the cathode of the floating diode D2 is grounded. The second end of the energy storage capacitor C2 is connected with the cathode (K) of the laser diode LD, the anode (A) of the laser diode LD is grounded, the anode of the laser diode LD is connected with the source electrode (S) of the MOS tube Q2, and the grid electrode (G) of the MOS tube Q2 is connected with the output end of the pulse generator TX_EN. The dynamic compensation capacitor C3 is connected across the source electrode and the drain electrode of the MOS transistor Q2.
It can be understood that the connection mode of the grounding of each component (such as the decoupling capacitor C1, the MOS tube Q1, the floating diode D2, the laser diode LD and the MOS tube Q2) in FIG. 4 can be changed to be connected with the negative electrode of the power supply, and the same function as the laser emitting circuit in FIG. 4 can be realized. Wherein it is understood that the negative electrode of the power supply may be grounded.
The capacitance value of the dynamic compensation capacitor C3 is smaller than that of the energy storage capacitor C2, and the capacitance value range of the dynamic compensation capacitor C3 may be between 2pF and 10nF, for example: the capacitance value of the dynamic compensation capacitor C3 is 100pF. The capacitance value of the storage capacitor C2 may range between 2pF and 20nF, for example: the capacitance value of the energy storage capacitor C2 is 2nF. The inductance value of the inductance L1 may range between 10nH and 100 μh, for example: the inductance value of the inductance L1 was 330nH. The parameter values of the above elements are only used as parameters, and the embodiments of the present application are not limited thereto.
The operation of the laser emission circuit of fig. 4 includes:
1. and (3) a charging stage.
The pulse generator TX_CHG sends rectangular pulses to the grid electrode of the MOS tube Q1, and controls the MOS tube Q1 to be in a conducting state, and the MOS tube Q2 is in a disconnecting state. The power supply VCC charges the inductor, and the decoupling capacitor C1 is connected between the positive electrode and the negative electrode of the power supply VCC in parallel, so that parasitic oscillation caused by a positive feedback path formed by the power supply VCC can be prevented. The decoupling circuit is capable of effectively eliminating parasitic coupling between circuits, in other words, the decoupling circuit can effectively eliminate parasitic coupling between circuits when current fluctuation formed in a power supply circuit affects normal operation of the circuits when current magnitudes of front and rear circuits are prevented from changing.
2. And (3) energy conversion stage.
After the charge is completed, the pulse generator tx_chg stops sending rectangular pulses to the MOS transistor Q1, and the MOS transistor Q1 is in an off state, and at this time, the MOS transistor Q2 is still in an off state. Because the current of the inductor L1 cannot be suddenly changed, the potential generated by the inductor L1 continues to be Δi to generate two paths of currents through the boost rectifier diode D1, one path charges the energy storage capacitor C2, the charging current passes through the boost rectifier diode D1, the energy storage capacitor C2, the floating diode D2 and forms a loop, and the laser diode LD is in a reverse bias cut-off state in the charging process of the energy storage capacitor C2. The other path of energy conversion charging current passes through parasitic capacitance C of MOS tube Q2 Q2-DS (not shown) and dynamic compensation capacitor C3 and formationAnother loop is passed through parasitic capacitance C of MOS transistor Q2 Q2-DS Is no longer flowing through the laser diode LD.
Obviously, the two paths of charging currents cannot flow through the laser diode LD, so that the laser diode LD cannot emit light at unexpected time, and the problem of laser light leakage is solved.
The improved laser emission circuit has the following characteristics: the laser diode LD is connected with the drain electrode of the MOS tube Q2 in the original mode, and is connected with the second end of the energy storage capacitor C2, the second end of the energy storage capacitor C2 is connected to the ground through the laser diode LD, namely the second end of the energy storage capacitor C2 is not directly grounded. Therefore, the laser emission circuit can also be called as a floating emission circuit for eliminating laser leakage, which is called as FCEL (float ground circuit for eliminating laser leakage).
3. And (3) energy release stage.
The pulse generator TX_EN sends rectangular pulses to the grid electrode of the MOS tube Q2, and controls the MOS tube Q2 to be in a conducting state, and the MOS tube Q1 is in a disconnecting state at the moment. The electric energy stored in the energy storage capacitor C2 forms an energy release (discharge) loop through the drain electrode and the source electrode of the MOS tube Q2, the laser diode LD and the second end of the energy storage capacitor C2, and the laser diode LD is driven to complete the laser emission action. In addition, the dynamic compensation capacitor C3 also forms a self-discharging loop through the drain electrode and the source electrode of the MOS tube Q2, and releases the stored electric energy during energy conversion so as to prepare for laser transmission in the next period.
The embodiment of the application also provides a laser radar which comprises the laser transmitting circuit.
Specifically, the laser emission circuit can be applied to a laser radar, and the laser radar can also comprise specific structures such as a power supply, processing equipment, optical receiving equipment, a rotating body, a base, a shell, man-machine interaction equipment and the like besides the laser emission circuit. It can be understood that the laser radar can be a single-path laser radar comprising a path of the laser transmitting circuit, and the laser radar can also be a multi-path laser radar comprising a plurality of paths of the laser transmitting circuits and corresponding control systems, wherein the specific number of the paths can be determined according to actual requirements.
According to the laser radar, the structure of the laser emission circuit is changed, the laser diode LD is connected with the drain electrode of the MOS tube Q2, the second end of the energy storage capacitor C2 is connected with the second end of the energy storage capacitor C2 through the cathode of the laser diode LD, the second end of the energy storage capacitor C2 is suspended through the laser diode LD, namely the second end of the energy storage capacitor C2 is not directly connected any more, and in the energy conversion stage, the parasitic capacitance of the energy release light-emitting element can not cause the laser diode to emit light in advance due to the energy conversion charging process, so that the laser diode is prevented from emitting light in unexpected time, and the problem of laser light leakage is solved.
Those skilled in the art will appreciate that implementing all or part of the above-described methods in accordance with the embodiments may be accomplished by way of a computer program stored on a computer readable storage medium, which when executed may comprise the steps of the embodiments of the methods described above. The storage medium may be a magnetic disk, an optical disk, a read-only memory, a random access memory, or the like.
The foregoing disclosure is illustrative of the present application and is not to be construed as limiting the scope of the application, which is defined by the appended claims.
Claims (8)
1. A laser emitting circuit, comprising:
the energy charging circuit is connected with the energy conversion circuit and used for storing electric energy; the charging circuit comprises a power supply, a decoupling capacitor, an inductor and a charging switching element; the positive electrode of the power supply is grounded through the decoupling capacitor, the positive electrode of the power supply is connected with the first end of the inductor, the second end of the inductor is grounded through the charging switch element, the negative electrode of the power supply is grounded, and the charging switch element is also connected with the charging pulse generator;
the energy conversion circuit is connected with the energy charging circuit and the energy releasing circuit and is used for converting the electric energy stored in the energy charging circuit into the energy conversion circuit; the energy conversion circuit comprises an energy storage capacitor and a floating diode, wherein the first end of the energy storage capacitor is connected with the energy charging circuit, and the first end of the energy storage capacitor is respectively connected with the first end of the energy release switch element and the second end of the inductor; the second end of the energy storage capacitor is connected with the anode of the floating diode, the second end of the energy storage capacitor is connected with the energy release circuit, and the cathode of the floating diode is grounded;
the energy release circuit is connected with the energy conversion circuit and is used for driving the laser diode to emit light by utilizing the electric energy stored in the energy conversion circuit; the energy release circuit comprises an energy release switch element and the laser diode, wherein the first end of the energy release switch element is connected with the first end of the energy storage capacitor, the second end of the energy release switch element is grounded, the second end of the energy release switch element is connected with the anode of the laser diode, and the cathode of the laser diode is connected with the second end of the capacitor; the energy release circuit further comprises a dynamic compensation capacitor, the dynamic compensation capacitor is connected with two ends of the energy release switch element in a bridging mode, and the energy release switch element is further connected with the energy release pulse generator; the laser emission circuit is in a charging stage, and the charging pulse generator sends a first rectangular pulse signal to the charging switching element to control the charging switching element to be conducted and the energy releasing switching element to be disconnected; in the energy conversion stage, the energy charging pulse generator stops sending rectangular pulse signals so as to disconnect the energy charging switching element and the energy discharging switching element; in the energy release stage, the energy release pulse generator sends a second rectangular pulse signal to the energy charging switch element so as to disconnect the energy charging switch element and connect the energy release switch element; and, in addition, the processing unit,
the charge pulse generator controls the on time of the charge switching element by controlling the width of the first rectangular pulse signal.
2. The laser emitting circuit of claim 1, wherein the energy conversion circuit further comprises a boost rectifier diode, an anode of the boost rectifier diode being connected to the energy charging circuit, and a cathode of the boost rectifier diode being connected to the first end of the energy storage capacitor.
3. The laser emission circuit according to claim 1, wherein the energy release switching element is a transistor, a collector of the transistor is connected to the first end of the energy storage capacitor, an emitter of the transistor is grounded and the emitter of the transistor is connected to an anode of the laser diode, and a base of the transistor is connected to an output end of the first pulse generator; or (b)
The energy release switch element is a transistor, an emitter of the transistor is connected with the first end of the energy storage capacitor, a collector of the transistor is grounded, the collector of the transistor is connected with the anode of the laser diode, and a base of the transistor is connected with the output end of the first pulse generator; or (b)
The energy release switching element is a gallium nitride switching tube, the drain electrode of the gallium nitride switching tube is connected with the first end of the energy storage capacitor, the source electrode of the gallium nitride switching tube is grounded, the source electrode of the gallium nitride switching tube is connected with the anode of the laser diode, and the grid electrode of the gallium nitride switching tube is connected with the output end of the first pulse generator.
4. The laser emission circuit according to claim 1, wherein the charge switching element is a transistor, a collector of the transistor is connected to the first end of the energy storage capacitor, an emitter of the transistor is grounded, and a base of the transistor is connected to an output end of the second pulse generator; or (b)
The energy charging switch element is a transistor, an emitter of the transistor is connected with the first end of the energy storage capacitor, a collector of the transistor is grounded, and a base of the transistor is connected with the output end of the second pulse generator; or (b)
The charging switch element is a gallium nitride switch tube, the drain electrode of the gallium nitride switch tube is connected with the first end of the energy storage capacitor, the source electrode of the gallium nitride switch tube is grounded, and the grid electrode of the gallium nitride switch tube is connected with the output end of the second pulse generator.
5. The laser transmitter circuit of claim 1, wherein the dynamic compensation capacitor has a capacitance value that is less than the capacitance value of the storage capacitor.
6. The laser transmitter circuit of claim 1, wherein the energy storage capacitor is comprised of a plurality of capacitors in parallel.
7. The laser emitting circuit of claim 2, wherein the boost rectifier diode and the floating diode are schottky diodes.
8. A lidar, comprising: a laser emitting circuit as claimed in any one of claims 1 to 7.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202311075092.5A CN117169857A (en) | 2019-10-17 | 2019-10-17 | Laser emission circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/CN2019/111738 WO2021051466A1 (en) | 2019-10-17 | 2019-10-17 | Laser emission circuit and lidar |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311075092.5A Division CN117169857A (en) | 2019-10-17 | 2019-10-17 | Laser emission circuit |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112805586A CN112805586A (en) | 2021-05-14 |
| CN112805586B true CN112805586B (en) | 2023-09-26 |
Family
ID=74884420
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201980064663.0A Active CN112805586B (en) | 2019-10-17 | 2019-10-17 | Laser emission circuit and laser radar |
| CN202311075092.5A Pending CN117169857A (en) | 2019-10-17 | 2019-10-17 | Laser emission circuit |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202311075092.5A Pending CN117169857A (en) | 2019-10-17 | 2019-10-17 | Laser emission circuit |
Country Status (2)
| Country | Link |
|---|---|
| CN (2) | CN112805586B (en) |
| WO (1) | WO2021051466A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116413677B (en) * | 2021-12-29 | 2024-02-06 | 深圳市速腾聚创科技有限公司 | Anode addressing driving circuit, addressable driving circuit and laser emitting circuit |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016152336A (en) * | 2015-02-18 | 2016-08-22 | 株式会社豊田中央研究所 | Laser diode driving circuit and laser radar device |
| DE102016116875A1 (en) * | 2015-09-22 | 2017-03-23 | Analog Devices, Inc. | Pulsed laser diode driver |
| CN206450825U (en) * | 2016-12-08 | 2017-08-29 | 北京万集科技股份有限公司 | A kind of bidifly light drive circuit and scanning type laser radar ranging equipment |
| CN109391006A (en) * | 2018-11-14 | 2019-02-26 | 深圳市速腾聚创科技有限公司 | Energy supply circuit and laser radar apparatus |
-
2019
- 2019-10-17 CN CN201980064663.0A patent/CN112805586B/en active Active
- 2019-10-17 WO PCT/CN2019/111738 patent/WO2021051466A1/en active Application Filing
- 2019-10-17 CN CN202311075092.5A patent/CN117169857A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2016152336A (en) * | 2015-02-18 | 2016-08-22 | 株式会社豊田中央研究所 | Laser diode driving circuit and laser radar device |
| DE102016116875A1 (en) * | 2015-09-22 | 2017-03-23 | Analog Devices, Inc. | Pulsed laser diode driver |
| CN206450825U (en) * | 2016-12-08 | 2017-08-29 | 北京万集科技股份有限公司 | A kind of bidifly light drive circuit and scanning type laser radar ranging equipment |
| CN109391006A (en) * | 2018-11-14 | 2019-02-26 | 深圳市速腾聚创科技有限公司 | Energy supply circuit and laser radar apparatus |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112805586A (en) | 2021-05-14 |
| WO2021051466A1 (en) | 2021-03-25 |
| CN117169857A (en) | 2023-12-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN113287237B (en) | Laser emission circuit and laser radar | |
| CN112805587B (en) | Laser emission circuit and laser radar | |
| CN111654193B (en) | Drive control method and circuit thereof | |
| CN104410252A (en) | Source electrode drive circuit and controlling method thereof | |
| CN109391006A (en) | Energy supply circuit and laser radar apparatus | |
| US20210328520A1 (en) | Acf converter, voltage conversion method, and electronic device | |
| CN110459955B (en) | High-power high-repetition-frequency semiconductor laser driving circuit | |
| CN112805586B (en) | Laser emission circuit and laser radar | |
| CN109450418B (en) | IGBT isolation driving circuit with switch control unit and control method thereof | |
| CN104201562A (en) | Semiconductor laser driving source with temperature compensation | |
| CN102136794B (en) | Charge pump driving circuit and charge pump system | |
| CN104539149A (en) | Top compensation circuit based on BUCK-BOOST and top compensation method of top compensation circuit | |
| CN113708603B (en) | Gate trigger circuit of thyristor | |
| CN111884637A (en) | Bootstrap circuit and power chip | |
| CN215378887U (en) | Pulse modulator with any pulse width | |
| CN220492852U (en) | Driving circuit and switching power supply | |
| WO2022133691A1 (en) | Switch circuit and switch power supply | |
| CN110932540B (en) | Bus soft start circuit with isolation applied to UPS | |
| KR102657175B1 (en) | DRIVING CIRCUIT FOR GaN FET | |
| CN220894754U (en) | Bias voltage generating circuit and laser radar | |
| US20240007101A1 (en) | Driver circuit and method for providing a pulse | |
| CN219999366U (en) | Radio frequency compensation circuit, device and terminal equipment | |
| CN115833574A (en) | Negative voltage converter capable of eliminating resonance and semiconductor chip | |
| CN112018596A (en) | Radiation driving circuit, radiation driving method and radiation emitting device | |
| CN116937951A (en) | Optical coupler isolated controllable charge pump circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |